SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '826c54623ba9e2df3f87659930542405b4395714c6b3f6d8f1f40b6c75da7d64' 
  AND token = 'T/m5HAA4IQU67uwHjcGltbYB2N6jGZvYvQvH9M1sG6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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