SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbdda73360b787d4d8ee651caf42137b0b26380917ef0d40bbe52f78e685980a' 
  AND token = 'NwXVEelQlCJqKxfyk0ruwgQAInAyYVj9z+oL7otGeFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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