SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '135abfaa1d203ca98ba6204747107d50ce01cab00037cabb768fb127298193f3' 
  AND token = 'nYymbRK2uS14JwAdnZan8ZWshGGMA+3UtCWxniOlRdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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