SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '665db0c93df8e21e38a719c60ade08c162e8ccdb2a8185c8160a1dd49fa4d267' 
  AND token = 'xQerz8w0iitEBcVTsFOcMFmRO0ksVerAOWbVDa/lb3k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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