SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '758149883b123d204856036475e0ac1578b93e6f5a0fe49a9198a2bca24421a6' 
  AND token = 'JIEQIP/JsbXvwKGV89J7pWdXQ7PVSGEfxg+MbzxGdBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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