SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ed8190d40b387fd09607db68382e75e8e6e2e90a167149a09dd076d77243cc63' 
  AND token = '5kCgeLUaaFToMMxJT7bL24IqBCOxZ0XkgQz3zsTmWnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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