SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f34a26803dfbafb598d4ddf7cf707dd359aa21a9bce6ffa6251059c8defde4f3' 
  AND token = 'T2eyHQclB1UXzapTayIgSj4fdVRHKTnrcL2K87YigRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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