SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dfa9a7f7beeaa0b4a762bccd00818892373373015a18136ca5c5ee2b42276d5' 
  AND token = 'WwJoDO2SUlFbt7YzHjnVV8/7BDGmikYjZivfZ5Ar1vs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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