SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '945c5354d520ae3891ace016d6bdd1c0fe244f4ebcb1c4d3a6f4fb88f5ce4484' 
  AND token = 'tzB4mefkJXEPrtBtKPjFSJmUjVyFtND6DWYy3L/7//k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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