SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af604c4bb2ff57213039dace24454964c8bf2e0ff0876f4ae4876808840bdd37' 
  AND token = '/7d9SBV0fTFwTxPQZyGbXcj2q3EXKs3PTZkC9gjFyjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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