SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c019f9e42750a68c405c12d764d0671234f536047d9054a75499b5704ea29cc3' 
  AND token = 'DFuXSgaphMFPGB3WIatlveRPY72QsnNsr877iY4Tq6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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