SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88b98d8e9613b3b5db8dad02468030a0ad0b97ea14ecd5296fe218245de759d1' 
  AND token = 'e4kjMKd8wSxYe44d9+dTunpphKiJbEq7o2WVm/NmRYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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