SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4315e45297c482f22ff2472f76a567b6345dd6af9d9a4340394f711f378bbfa' 
  AND token = 'dlxHCJCdDz1aX/KXaqXowcVj2gZHr9AOg7A3A158bY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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