SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0104a933d94cde4f937cd23f6c934ab6214d11bdc672ac281a61609ddc48c6fb' 
  AND token = 'NHb0L1a2OIu/jOPb2PUIX9EHX1sNTFAkqTVBu+58zHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}