SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3e741dcd68ae97b8cc3575fd5a50bf128bff979967675330f271679119f2185' 
  AND token = 'V+PLPiiimIpZ+2Kqzx3aTRFnAJhQnXkZsxylQbk8nIk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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