SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daa3124edcdc3fced7af53f10fc4233d58c0318c23c9aa57237c1f599960b4fc' 
  AND token = 'LORh047WJgYxIzrJeTA59tkEUW5/DXHiuzXrOZBLjLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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