SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f561bb4b52aa477e94d08a9bd7b25da70384c9ded486d510037976c6e959473e' 
  AND token = 'z10tyZb49x0ykksYexz+WW76TsmTde2ickpKUkbel9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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