SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a955f657db4d19f4af138a147ea58f45a7a6989dcf784393b0333a42840d4963' 
  AND token = 'UEUVpYICvzzHO/j6q1dJeTv5B0hhDGYqZ01sVfMOOHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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