SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e25a86ec5c945f0f249ccacfc72467d0ffb547da98a025ea5c0e7d408d8242f' 
  AND token = 'bPqXDE8aTZbfWUZ3ezthLciFN1kCiyWmgyDmd/bdKDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}