SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9b93de896dc8282d9b50215b408897031c7f9b33b97dbf3e717be523dccf7a8' 
  AND token = 'LTJzFEdvfYsCRdiAkdR6v/MgRrcOWVlXeIQbjFur7aY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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