SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a9073ba16206ec2ac34d457704ed805a5d36956c3316dd5285388722a9cc686' 
  AND token = 'n34C0Y6BEKB+piPvzTzq0nt+EUZJI0igL3uhNgFkfxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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