SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e55c22ff8566a76e9724550aee4e693ae27c0f9e339207980436b08928d7bbfd' 
  AND token = 'NoGLnmcHNMkhFEcrjOT0/qN+J+875lttVveZqLbt5lI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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