SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02e12764dac6d6ba96c90516e7e20007b31415826a9f88ca5fd595cf2c74b5ee' 
  AND token = 'a8+GLrXIY7PYeIFhlQNTvZqi916lpvcspV3qH24KUPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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