SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a77378424d39b4288862fbd4dbe35bda965f2af6c7bb2a138144ea0128e458d0' 
  AND token = 'JYzHv9r7a//NKUGzuoq8AAtg3eV8H8MMTqD64x7djng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}