SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f63d30fa52307edfb3215ecc030323243db2cd8d241f9056935cb5cb149a65ba' 
  AND token = 'sT1Ft0SlBaSgFYWVZIL0VXFCBleLnkMpz7M21mnWKds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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