SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddec4171faf3a5bff37f33b1e8e016e93d4a1d390b4edca0badf90d06151c441' 
  AND token = 'i4rSykT9o7gRL+1StGfmSeZUNQRF5NnxVBA6kGii1TM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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