SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6e869add112bb766b4cf68abf0c0324ecd761a3f4588117f52e22153af1f68bf' 
  AND token = 'c64YAwXhGoDP/CVcAfBObJuWLKUd/mzoAgL/kgU+5Hk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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