SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80e6dffb500825dec82253a223ce15c7d950b4c9859a2fa62377eeae5e1341c2' 
  AND token = 'dc8mMA5ZslBTpmQ5r6OybGtwGymV3Gdhxg0pJHpCUYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00087

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}