SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '271f95d6a16c9882d54d2238bd1700d7b6ea2e8f17ebf33f9735dd766b4f1701' 
  AND token = '33oCf9QTUO/J+NMgj/BI5fQ3YmchSXcbB6COyVG8uqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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