SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd6689834e55cd64fa3142edebfe81cad09a970fdc24356d193c1dd1529eaea4' 
  AND token = 'hqwis+x4FHSmvigMS7nyoWXtg1QgmD8455ZIdGYWEYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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