SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a1fb81c586e318dbe6ead9468bdac6e2840703229406f04159a1ad286169b1f' 
  AND token = '1vtoxWqpibu608pirHMTf4Pfl0jnT3ZjsEoP/1MPJSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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