SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c889158cc8be3c7302217866a44f6d2a086610075798a1cea54341c4fa0727a0' 
  AND token = 'yy70apbCCFnv+KcvQkf/c0CV4QYMsl+oZq4dn0bzt08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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