SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7b8a4725ac46fd5e129418c946d7a93f4159624e41b7659fe7325ddd076803f' 
  AND token = 'pdPsrrfyl3L/kV2+PSpJdPujoUBcWJQC4LJKwfykNIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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