SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8caebab6f36cc02883e09c99b38fe97670c7a74316624a497af5b1c23d866e2' 
  AND token = 'UPITLl7y5vdrQzWRkOMRm7I1SKDzVPS83/CZjzJVq+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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