SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3cc78027b9f7c557f7f900b5c0d45765cc62107fb767cdfe88941fb3454c884' 
  AND token = 'izgy95unCjIg0v4sBypJvYBct4UWUoAZCWHrBp53zKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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