SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7ce93d4b518e4ce7f06b9b1a817caa4a6e7cfacbf6ec1b12193f2943ff42ec8' 
  AND token = 'VIKUYijApOm6zTEf9hRjGsqsqQkIZSsC0RgshR0Hp/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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