SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbf9c37f9b2f0e7c803d58c7efc87b02b7da6ab061a68b4d66bc7ba95f19c88f' 
  AND token = 'PrAu5Eqsz6uUDXT3Be0pzbYKvtemzmwjkwJALbtYAn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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