SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9686cb627ac7ec736e5cd8eea467c054bfab5d043a1370177741e05988d34a6' 
  AND token = 'nMrxnTcoo+FA/MTbK+3huMk0jhDWBG/NilCVB/b9KJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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