SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be7898085566f76c3e443bb395c64ca7163409f2a0f092cf5814a834f0bbbb4e' 
  AND token = 'tM58lbOXf9JJs3/+BkGtToXZTEJUldgATf7ZGQxeOHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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