SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '116fb512ef2fcc5684cda69797457321fe04d166dbed828db345edc6a768aa6b' 
  AND token = 'Jcp70xvuPEzUK4F+vzy86B4bEcfObIyOM9UggNGU95Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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