SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b299a486a4d354feb8852d1b9db170fb2e1d8bfee21693e83f25b31bcc43466' 
  AND token = 'DDr5+thSB5Pif5VH2Ll8BMb4vvZjJRPzo3zeHFXVGeY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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