SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4012f14586b65f1273944eeec7aab819f76af97c229bcce41e9a1ff98e995594' 
  AND token = 'Scu0ZoPzVGNMqM9JAiLfEBQpsWPFUd7+m/vjHI2py7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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