SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47069fda3da82952bbb34c3b3522a61f0d4c18fabaa44d23450a549640738606' 
  AND token = '0HMXwp/j6CDrpGrvYlk8DLVJcj4qHHHihzZQsgjAJZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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