SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77bdc025b9fdb242fa897d971b42fc717ac75d0b045270ced8ad34225d4ed0c1' 
  AND token = 'yFnIXHKtFafbni2KEjCXYNKemd9eAW1JYRuBBPmSaPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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