SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7cc1735a893af60c6d85cb94d695797095b1402d304eb4ee546a493ca4fd0e3' 
  AND token = 'mam+ASrKCNb+96M3+uRwruwUZ8rO5fwoSCMHIcKmdvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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