SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ffb2df192894cb05e6892c3e5b0b165c3e0781fc62d9a06e4354eb60553d23e' 
  AND token = 'QKeAPH94n/uR7tFIJCXjvqwspJ2UY7p/EBHZbOdEnys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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