SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a38fbd0e14c9adc3bf4961669cbaa7d2a9f28f79e9488fcc9bb73fdcc5a72cc3' 
  AND token = 'AT54DjCmFIdi+C/dreGqRKvwQRphOXY+6zNAchu9KcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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