SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce2c6c9a17b648c0176d854b1642ef5d81df88527a2b4bfd1070b9eeb8503070' 
  AND token = 'Q4eEC8WSCxYPgGXQMVn+HzouY6MmkcCaL5jZQlRgE6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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