SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ad1345bcaf748b45430b53e8ab4e1f586dc68553d65f3c2c4784e7fc4de278f' 
  AND token = 'LptybLsQSvKeFG7YUUlNYlckKjldAEwSB20Shj0xOSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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