SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '96e8c9d54f239b62fbb702a9a1cc68d6af943f8d3cb2aa777ac0431c6483d563' 
  AND token = '2p6Qs/MvIS8D4j/nE466YEY2DiTPR3O+Nr4RRDLWcCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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