SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a850315f643e3702a7d653449f32b1b8584f28c24364a514815c9d96bdbcd964' 
  AND token = 'jvxcyPKFanxLoBPzaSFj9Guv3ml3AUsPtD66Q9rNEGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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