SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b191019cdf5b43fd77605834ecdc158c21afc01f33d39fb38454890fd7f5defd' 
  AND token = '5TLa7ouNZlMPzOfSm0I6BIvV8DEbAzNw42YvonzBtHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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