SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d8869fcbfec160f6d802a200b8f9a0860cf788259aeb8b724b995aeeacc4468' 
  AND token = '65nDqTs1wK2fc5iEtaZhJA9CfkNv2ePwzGmPEUORXw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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