SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea817b015c4b3157cb6862a4c18acf42335d902973bb1517c00e8efd37070b19' 
  AND token = 'R+9muXqGVDZoNpCJBPlauzDsqs/7sUfEFhxP22XozRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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