SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25594d1a33f3cbd64d41b46384ad47cf5cece65e5c92fda62bb5c778b4e09d1a' 
  AND token = '/TRImQJxiWU39SGPU/miGUP41nGz/Vf4Yjla+YGbrAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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