SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57047a5f037ccfb6ec65dc3050abfa836f7499a579d4dfaa80bde348b3170145' 
  AND token = '96yIU0u8zJ0M9MSzc0cjI0sRMS5P5vEtBlxhOHnzk8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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