SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1d69ff687d4d85b0d1e9d2c31bda47c767a1c0f94f360e2e18ad05875673303' 
  AND token = 'hFEpvOAbKEF8JKOWeGu9i96jap91theyya1+9+kVbRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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