SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf25732abed7936ceff273ff63d324d79e63bddfd818fb2c39559e7434c65a23' 
  AND token = 'fLUSc5PLhSzXjaQrIBaHBrWp1TN7+eoQjvDLQzG5JKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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