SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcc7e4e9977bd9c45eaad905b381fff748201af2ef14c70399fc75373275715a' 
  AND token = 'GWxXQ53fgLrTlDCmNac0CS5dNG/Uga0A3oIH3h3qK6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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