SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57396bd6a468b98b1ee22a19369b3a4bdef3d89f8deafd1177ceeb0cb94ea781' 
  AND token = 'XNLTDT2yID7GiZk9aV5jFNA5Ult3YLkcz0TMhr2iWHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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