SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c75443652a2239cade5995171a667aba2480664533d92259d9b18b2fe94ae4f5' 
  AND token = 'FbGM8tKwnshBZSprMDVEdgiQHl2jh7rsT4F8fB6xNQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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