SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf829cdbff0313bd8c74c957c22a6f0fede57f7c0e89550382ca72364804e999' 
  AND token = 'Fh5KpA/jhwMVeBwcIBfXEkWZ45c16IJTYapPbVfeqMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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