SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '752f90dfe9204731c315b86473ab91e126e9adbfda48504abcbb3f856c22c1f8' 
  AND token = 'AhDqkqIFUY1wz65hd3X1KhdyAnnjN5C2Lqf0J0LXRRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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