SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9eac025ea6e8f675331759153f387fb7fc58e58eb9d3a923b5704dd70f9f8a13' 
  AND token = '+pApowobhGixWFurVbOoT+Wfrap9C1TFixkhHsyIDUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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