SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afd5f4d9a2c8d6fd07f22fd737f4e1863fb88dfb42f05736b1cf17fb88d3e3d7' 
  AND token = 'zpYvs+Hu7mswKHOiTJFjTBWBliAqoFeyNRIeqXOBmqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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